Tin-mono-sulfide (SnS) Thin Films Prepared by Chemical Spray Pyrolysis with Different [S]/[Sn] Ratios

[EN] SnS thin films were deposited by chemical spray pyrolysis using cost-effective and low-toxicity sources materials like tin (II) chloride dihydrate and thiourea as sources of tin and sulphur, respectively. We have studied the properties of sprayed SnS thin films with [S]/[Sn] ratios were varied from 1 to 4 in order to optimize these parameters. X-ray diffraction was used for analyzing the films structure, Raman Spectroscopy for assessing the films quality and structure, scanning electron microscope (SEM) for surface morphology and energy dispersive energy (EDS) for compositional element in samples, atomic force microscopy (AFM) for the topography of surfaces and optical spectroscopy for measuring transmittances and then deducing the band gap energies. All films obtained are polycrystalline with (111) as preferential direction for films with [S]/[Sn] ratio equals to one while for [S]/[Sn] ratios from 2 to 4 the main peak becomes (101) and the (111) peak decreases in intensity. Raman spectroscopy confirms the presence of only one SnS phase without any additional parasite secondary phases. SEM images revealed that films are well adhered onto glass surface with rounded grain. AFM confirms this result being films with [S]/[Sn] = 1 the roughest and also with the largest grain size. EDS results show an improvement of stoichiometry with the increase of the [S]/[Sn] ratio. From optical analysis, it is inferred that the band gap energy decreases from 1.83 to 1.77 eV when the [S]/[Sn] ratio changes from 2 to 4.This work was supported by Ministerio de Economia y Competitividad (ENE2016-77798-C4-2-R) and Generalitat valenciana (Prometeus 2014/044).Sall, T.; Mollar García, MA.; Marí, B. (2017). Tin-mono-sulfide (SnS) Thin Films Prepared by Chemical Spray Pyrolysis with Different [S]/[Sn] Ratios. Optical and Quantum Electronics. 49(11). https://doi.org/10.1007/s11082-017-1219-9S3864911Avellaneda, D., Nair, M.T.S., Nair, P.K.: Polymorphic tin sulfide thin films of zinc blende and orthorhombic structure by chemical deposition. J. Electrochem. Soc. 55, D517–D525 (2008)Brownson, J.R.S., Georges, C., Levy-Clement, C.: Synthesis of δ-SnS polymorph by electrodeposition. Chem. Mater. 18, 6397–6402 (2006)Chandrasekhar, H.R., Humphreys, R.G., Zwick, U., Cardona, M.: Infrared and Raman spectra of the IV-VI compounds SnS and SnSe. Phys. Rev. B 15, 2177–2183 (1977)Gao, C., Shen, H., Sun, L., Huang, H., Lu, L., Cai, H.: Preparation of SnS films with zinc blende structure by successive ionic layer adsorption and reaction method. Mater. Lett. 64, 2177–2179 (2010)Koteeswara Reddy, N., Ramesh, K., Ganesan, R., Reddy, K., Gunasekhar, K.R., Gopal, E.: Synthesis and characterization of co-evaporated tin sulphide thin films. J. Appl. Phys. A 83, 133–138 (2006)Loferski, J.J.: Theoretical considerations governing the choice of the optimum semiconductor for photovoltaic solar energy conversion. J. Appl. Phys. 27, 777–784 (1956)Malaquias, J., Fernandes, P.A., Salome, P.M.P., da Cunha, A.F.: Assessment of the potential of tin sulphide thin films prepared by sulphurization of precursors as cell absorbers. Thin Solid Films 519, 7416–7420 (2011)Mathews, N.R., Anaya, H.B.M., Cortes-Jacome, M.A., Angeles-Chavez, C., Toledo-Antonio, J.A.: Tin sulfide thin films by pulse electrodeposition: structural, morphological, and optical properties. J. Electrochem. Soc. 157, H337–H341 (2010)Reddy, K.T.R., Reddy, N.K., Miles, R.W.: Photovoltaic properties of SnS based solar cells. Sol. Energy Mater. Sol. Cells 9, 3041–3046 (2006)Sall, T., Mollar, M., Marí, B.: Substrates influences on the properties of SnS thin films deposited by chemical spray pyrolysis technique for photovoltaic applications. J. Mater. Sci. 51, 7607–7613 (2016)Sinsermsuksakul, P., Heo, J., Noh, W., Hock, A.S., Gordon, R.G.: Atomic layer deposition of tin monosulfide thin films. Adv. Energy Mater. 1, 1116–1125 (2011)Sivaramasubramaniam, R., Muhamad, M.R., Radhakrishna, S.: Optical properties of annealed tin (II) oxide in different ambients. Phys. Status Solidi (a) 136, 215–222 (1993)Ullah, H., Marí, B.: Numerical analysis of SnS based polycrystalline solar cells. Superlattices Microstruct. 72, 148–155 (2014

Substrate Influences on the Properties of SnS Thin Films Deposited by Chemical Spray Pyrolysis Technique for Photovoltaic Applications

The final publication is available at Springer via http://dx.doi.org/10.1007/s10853-016-0039-9.Herein, we report on tin monosulfide (SnS) thin films elaborated by the Chemical Spray Pyrolysis (CSP) technique onto various substrates as simple glass, ITO-, and Mo-coated glasses in order to study the influence of substrates on the physical and chemical properties of Sns thin films. Structural analysis revealed that all films crystallize in orthorhombic structure with (111) as the sole preferential direction without secondary phases. In addition, film prepared onto pure glass exhibits a better crystallization compared to films deposited onto coated glass substrates. Raman spectroscopy analysis confirms the results obtained by X-ray diffraction with modes corresponding well to SnS single crystal orthorhombic ones (47, 65, 94, 160, 186, and 219 cm21) without any additional parasite secondary phase like Sn2S3 or SnS2. Field emission scanning electron microscope revealed that all films have a cornflake-like particles surface morphology, and energy dispersive X-ray spectroscopy analysis showed the presence of sulfur and tin with a nearly stoichiometric ratio in films deposited onto pure glass. High surface roughness and large grains are observable in film deposited onto glass. From optical spectroscopy, it is inferred that band gap energy of SnS/glass and SnS/ITO were 1.64 and 1.82 eV, respectively.This work was supported by Ministerio de Economia y Competitividad (ENE2013-46624-C4-4-R) and Generalitat valenciana (Prometeus 2014/044).Sall, T.; Mollar García, MA.; Marí, B. (2016). Substrate Influences on the Properties of SnS Thin Films Deposited by Chemical Spray Pyrolysis Technique for Photovoltaic Applications. Journal of Materials Science. 51(16):7607-7613. https://doi.org/10.1007/s10853-016-0039-9S760776135116Reddy KTR, Prathap P, Miles RW (2010) Thin films of tin sulphide for application in photovoltaic solar cells in Photovoltaics. In: Tanaka H, Yamashita K (eds) Photovoltaics: developments, applications and impact. Nova Science, New York, pp 1–27Herzenberg R (1932) Rev Miner 4:33Juarez AS, Silver AT, Ortiz A (2005) Fabrication of SnS 2 /SnS heterojunction thin film diodes by plasma-enhanced chemical vapor deposition. Thin Solid Films 480–481:452–456Mathews NR, Anaya HBM, Cortes-Jacome MA, Angeles-Chavez C, Toledo-Antonio JA (2010) Tin sulfide thin films by pulse electrodeposition: structural, morphological, and optical properties. J Electrochem Soc 157:H337–H341Reddy NK, Ramesh K, Ganesan R, Reddy K, Gunasekhar KR, Gopal E (2006) Synthesis and characterization of co-evaporated tin sulphide thin films. Appl Phys A 83:133–138Ramakrishna Reddy KT, Koteswara Reddy N, Miles RW (2006) Photovoltaic properties of SnS based solar cells. Sol Energy Mater Sol Cells 90:3041–3046Ullah H, Marí B (2014) Numerical analysis of SnS based polycrystalline solar Cells. Superlattice Microst 72:148–155Avellaneda D, Nair MTS, Nair PK (2008) Polymorphic tin sulfide thin films of zinc blende and orthorhombic structures by chemical deposition. J Electrochem Soc 155:D517–D525Sinsermsuksakul P, Heo J, Noh W, Hock AS, Gordon RG (2011) Atomic layer deposition of tin monosulfide thin films. Adv Energ Mater 1:1116–1125Jeyaprakash BG, kumar RA, Kesavan K, Amalarani A (2010) Structural and optical characterization of spray deposited SnS thin film. J Am Sci 6:22–26Hibbert TG, Mahon MF, Molloy KC, Price LS, Parkin IP (2001) Deposition of tin sulfide thin films from novel, volatile (fluoroalkythiolato) tin (IV) precursors. J Mater Chem 11:469–473Senthilarasu S, Hahn YB, Lee SH (2007) Structural analysis of zinc phthalocyanine (ZnPc) thin films: x-ray diffraction study. J Appl Phys 102:043512Willeke G, Dasbach R, Sailer B, Bucher E (1992) Thin pyrite (FeS2) films prepared by magnetron sputtering. Thin Solid Films 213:271–276Chowdhury A, Biswas B, Majumder M, Sanyal MK, Mallik B (2012) Studies on phase transformation and molecular orientation in nanostructured zinc phthalocyanine thin films annealed at different temperatures. Thin Solid Films 520:6695–6704Deepa KG, Vijayakumar KP, Kartha CS (2012) Lattice vibrations of sequentially evaporated CuInSe2 by raman microspectrometry. Mat Sci Semicond Proc 15:120–124Nikolic PM, Lj Miljkovic P, Mihajlovic Lavrencic B (1977) Splitting and coupling of lattice modes in the layer compound SnS. J Phys C 10:L289–L292Chandrasekhar HR, Humphreys RG, Zwick U, Cardona M (1977) Infrared and raman of IV-IV compounds SnS and SnSe. Phys Rev B 15:2177–2183Revathi N, Bereznev S, Iljina J, Safonova M, Mellikov E, Volobujeva O (2013) PVD grown SnS thin films onto different substrate surfaces. J Mater Sci: Mater Electron 24:4739–4744Wang Y, Gong H, Fan BH, Hu GX (2010) Photovoltaic behavior of nanocrystalline SnS/TiO2. J Phys Chem C 114:3256–3259Tanusevski A, Poelman D (2003) Optical and photoconductive properties of SnS thin films prepared by electron beam evaporation. Sol Energy Mater Sol Cells 80:297–303Sajeesh TH, Poornima N, Kartha CS, Vijayakumar KP (2010) Unveiling the defect levels in SnS thin films for photovoltaic applications using photoluminescence technique. Phys Status Solidi A 207:1934–1939Sinsermsuksakul P, Heo J, Noh W, Hock AS, Gordon RG (2011) Atomic layer deposition of tin monosulfide thin films. Adv Energy Mater 1:116–125Bashkirov Simon A, Lazenka Vera V, Gremenok Valery F, Bente Klaus (2011) Microstructure of SnS thin films obtained by hot wall vacuum deposition method. J Adv Microsc Res 6:153–158Sall T, Marí Soucase B, Mollar M, Hartitti B, Fahoume M (2015) Chemical spray pyrolysis of B-In2S3 thin films deposited at different temperatures. J Phys Chem Solids 76:100–10

Opto-electrical characterisation of In-doped SnS thin films for photovoltaic applications

[EN] Spray pyrolised SnS thin films doped with indium were studied using various optical and electrical techniques.Structural analysis shows that all films crystallise in an orthorhombic structurewith (111) as a preferential direction, without secondary phases. The doping of SnS layers with indium results in better morphology with increased grain size. Absorption measurements indicate a dominant direct transition with energy decreasing from around 1.7 eV to 1.5 eV with increased indium supply. Apart from the direct transition, an indirect one, of energy of around 1.05 eV, independent of indiumdoping, was identified. The photoluminescence study revealed two donors to acceptor transitions between two deep defect levels and one shallower one, with an energy of around 90 meV. The observed transitions did not depend significantly on In concentration. The conductivitymeasurements reveal thermal activation of conductivity with energy decreasing from around 165 meV to 145 meV with increased In content.This work was supported by the Ministerio de Economia y Competitividad (ENE2016-77798-C4-2-R) and Generalitat Valenciana (Prometeus 2014/044).Urbaniak, A.; Pawlowski, M.; Marzantowicz, M.; Sall, T.; Marí, B. (2017). Opto-electrical characterisation of In-doped SnS thin films for photovoltaic applications. Thin Solid Films. 636:158-163. https://doi.org/10.1016/j.tsf.2017.06.001S15816363

SnS Thin Films Prepared by Chemical Spray Pyrolysis at Different Substrate Temperatures for Photovoltaic Applications

[EN] The preparation and analysis of morphological, structural, optical, vibrational and compositional properties of tin monosulfide (SnS) thin films deposited on glass substrate by chemical spray pyrolysis is reported herein. The growth conditions were evaluated to reduce the presence of residual phases different to the SnS orthorhombic phase. X-ray diffraction spectra revealed the polycrystalline nature of the SnS films with orthorhombic structure and a preferential grain orientation along the (111) direction. At high substrate temperature (450A degrees C), a crystalline phase corresponding to the Sn2S3 phase was observed. Raman spectroscopy confirmed the dominance of the SnS phase and the presence of an additional Sn2S3 phase. Scanning electron microscopy (SEM) images reveal that the SnS film morphology depends on the substrate temperature. Between 250A degrees C and 350A degrees C, SnS films were shaped as rounded grains with some cracks between them, while at substrate temperatures above 400A degrees C, films were denser and more compact. Energy-dispersive x-ray spectroscopy (EDS) analysis showed that the stoichiometry of sprayed SnS films improved with the increase of substrate temperature and atomic force microscopy micrographs showed films well covered at 350A degrees C resulting in a rougher and bigger grain size. Optical and electrical measurements showed that the optical bandgap and the resistivity decreased when the substrate temperature increased, and smaller values, 1.46 eV and 60 Omega cm, respectively, were attained at 450A degrees C. These SnS thin films could be used as an absorber layer for the development of tandem solar cell devices due to their high absorbability in the visible region with optimum bandgap energy.This work was supported by Ministerio de Economia y Competitividad (ENE2013-46624-C4-4-R) and Generalitat valenciana (Prometeus 2014/044).Sall, T.; Marí, B.; Mollar García, MA.; Sans-Tresserras, JÁ. (2017). SnS Thin Films Prepared by Chemical Spray Pyrolysis at Different Substrate Temperatures for Photovoltaic Applications. Journal of Electronic Materials. 46(3):1714-1719. https://doi.org/10.1007/s11664-016-5215-9S17141719463N.R. Mathews, H.B.M. Anaya, M.A. Cortes-Jacome, C. Angeles-Chavez, and J.A. Toledo-Antonio, J. Electrochem. Soc. 157, H337 (2010).N. Koteeswara Reddy, K. Ramesh, R. Ganesan, K. Reddy, K.R. Gunasekhar, and E. Gopal, Appl. Phys. A 83, 133 (2006).J.J. Loferski, J. Appl. Phys. 27, 777 (1956).K.T.R. Reddy, N.K. Reddy, and R.W. Miles, Sol. Energy Mat. Sol. C 90, 3041 (2006).C. Gao, H.L. Shen, L. Sun, H.B. Huang, L.F. Lu, and H. Cai, Mater. Lett. 64, 2177 (2010).D. Avellaneda, M.T.S. Nair, and P.K. Nair, J. Electrochem. Soc. 155, D517 (2008).J.R.S. Brownson, C. Georges, and C. Levy-Clement, Chem. Mater. 19, 3080 (2007).P. Sinsermsuksakul, J. Heo, W. Noh, A.S. Hock, and R.G. Gordon, Adv. Eng. Mat 1, 1116 (2011).T. Sall, M. Mollar, and B. Marí, J. Mater. Sci. 51, 7607 (2016).K. Otto, A. Katerski, O. Volobujeva, A. Mere, and M. Krunks, Energy Proc. 3, 63 (2011).J. Malaquias, P.A. Fernandes, P.M.P. Salomé, and A.F. da Cunha, Thin Solid Films 519, 7416 (2011).T.H. Sajeesh, A.R. Warrier, C. Sudha Kartha, and K.P. Vijayakumar, Thin Solid Films 518, 4370 (2010).M. Vasudeva Reddy, G. Sreedevi, C. Park, R.W. Miles, and K.T. Ramakrishna Reddy, Curr. Appl. Phys. 15, 588 (2015).A. Molenaar, Extended Abstracts, vol. 84-2, Pennington, N.J., 634 (1984)S. López, S. Granados, and A. Ortiz, Semicond. Sci. Technol. 11, 433 (1996).B. Cullity, Elements of X-ray Diffraction (New York: Addision-Wesley Publishing Company Inc, 1967), p. 501.G. Willeke, R. Dasbach, B. Sailer, and E. Bucher, Thin Solid Films 213, 271 (1992).H.R. Chandrasekhar, R.G. Humphreys, U. Zwick, and M. Cardona, Phys. Rev. B 15, 2177 (1977).S. Cheng and G. Conibeer, Thin Solid Films 520, 837 (2011)

Synthesis of Perfectly Oriented MAPb0.93Cr0.07Br3 Perovskite Crystals for Thin-Film Photovoltaic Applications

[EN] Wide band gap methylammonium lead halide perovskites (CH3NH3PbX3, X=halogen; CH3NH3: MA) are interesting materials for photovoltaic applications. They have recently gained substantial attention because of their high efficiency, low cost, superior optical properties. The most attractive and representative perovskites are methylammonium lead halides (CH3NH3PbX3,) denoted as MAPbX3, X = Br, Cl, I. usually the optical and structural properties of CH3NH3PbBr3 can be adjusted by introducing other extrinsic ions such as chloride and bromide. In this work, instead of replacing the halogens I or Cl with bromine (Br) as usual, we preferred to act on the post-transition metal (Pb). To this end, we replaced lead with chromium (Cr) which is a transition metal and may have the same oxidation state (+2) as lead. MAPb0.93Cr0.07Br3 thin films were deposited on ITO substrate by the spin coating process. X-ray diffraction analyses indicated the formation of a cubic perovskite with space group Pm3 m. The structural analysis reveals films with (110) and (220) as main peaks. Deposited films showed a strong absorbance in the UV¿vis range. The band gap values were estimated from absorbance measurements. It was found between 1.60 and 1.80 eV. SEM analysis shows a morphology with good coverage and no apparent crystal orientation.Soro, D.; Sidibé, M.; Fassinou, W.; Marí, B.; Sall, T.; Fofana, B.; Boko, A.... (2017). Synthesis of Perfectly Oriented MAPb0.93Cr0.07Br3 Perovskite Crystals for Thin-Film Photovoltaic Applications. International Journal of Innovative Research in Science, Engineering and Technology. IJIRSET (Online). 6(6):10170-10176. doi:10.15680/IJIRSET.2017.0606007S10170101766

A molecular method to discriminate between mass-reared sterile and wild tsetse flies during eradication programmes that have a sterile insect technique component

Background The Government of Senegal has embarked several years ago on a project that aims to eradicate Glossina palpalis gambiensis from the Niayes area. The removal of the animal try-panosomosis would allow the development more efficient livestock production systems. The project was implemented using an area-wide integrated pest management strategy including a sterile insect technique (SIT) component. The released sterile male flies originated from a colony from Burkina Faso. Methodology/Principal Findings Monitoring the efficacy of the sterile male releases requires the discrimination between wild and sterile male G.p. gambiensis that are sampled in monitoring traps. Before being released, sterile male flies were marked with a fluorescent dye powder. The marking was however not infallible with some sterile flies only slightly marked or some wild flies contaminated with a few dye particles in the monitoring traps. Trapped flies can also be damaged due to predation by ants, making it difficult to discriminate between wild and sterile males using a fluorescence camera and / or a fluorescence microscope. We developed a molecular technique based on the determination of cytochrome oxidase haplotypes of G. p. gambiensis to discriminate between wild and sterile males. DNA was isolated from the head of flies and a portion of the 5' end of the mitochondrial gene cytochrome oxidase I was amplified to be finally sequenced. Our results indicated that all the sterile males from the Burkina Faso colony displayed the same haplotype and systematically differed from wild male flies trapped in Senegal and Burkina Faso. This allowed 100% discrimination between sterile and wild male G. p. gambiensis. Conclusions/Significance This tool might be useful for other tsetse control campaigns with a SIT component in the framework of the Pan-African Tsetse and Trypanosomosis Eradication Campaign (PATTEC) and, more generally, for other vector or insect pest control programs

Synthesis and X-ray structure of the dysprosium(III) complex derived from the ligand 5-chloro-1,3-diformyl-2-hydroxybenzene-bis-(2-hydroxybenzoylhydrazone) [Dy2(C22H16ClN4O5)3]

The title compound [Dy2(C22H16ClN4O5)3](SCN)3(H2O)(CH3OH) has been synthesized and its crystal structure determined by single X-ray diffraction at room temperature. The two nine coordinated Dy(III) are bound to three macromolecules ligand through the phenolic oxygens of the p-chlorophenol moieties, the nitrogen atoms and the carbonyl functions of the hydrazonic moieties. The phenolic oxygen atoms of the 2-hydroxybenzoyl groups are not bonded to the metal ions. In the bases of the coordination polyhedra the six Dy-N bonds are in the range 2.563(13)-2.656(13) Å and the twelve Dy-O bonds are in the range 2.281(10)-2.406(10) Å. KEY WORDS: Dysprosium(III) complex, 5-Chloro-1,3-diformyl-2-hydroxybenzene-bis-(2-hydroxybenzoylhydrazone), Crystal structure  Bull. Chem. Soc. Ethiop. 2003, 17(2), 167-172